Kusangalatsa kwa ma harmonics achiwiri mumitundu yambiri

Kusangalatsa kwa ma harmonics achiwiri mumitundu yambiri

Chiyambireni kupezeka kwa mawonekedwe achiwiri osagwirizana ndi mawonekedwe a 1960s, kwadzutsa chidwi chachikulu cha ofufuza, mpaka pano, kutengera mawonekedwe achiwiri a harmonic, ndi pafupipafupi, apanga kuchokera ku ultraviolet kwambiri mpaka gulu lakutali la infrared.lasersimathandizira kwambiri kukula kwa laser,kuwalakukonza zidziwitso, kujambula kwapang'onopang'ono kwapamwamba kwambiri ndi magawo ena. Malinga ndi nonlinearopticsndi chiphunzitso cha polarization, mawonekedwe owoneka bwino osasinthika amalumikizana kwambiri ndi ma crystal symmetry, ndipo coefficient yosagwirizana ndi zero sizomwe zimangokhala pakatikati pa inversion symmetric media. Monga chofunikira kwambiri chachiwiri chopanda mzere, ma harmonics achiwiri amalepheretsa kwambiri mbadwo wawo komanso kugwiritsa ntchito bwino mu ulusi wa quartz chifukwa cha mawonekedwe aamorphous ndi symmetry of center inversion. Pakali pano, njira polarization (optical polarization, matenthedwe polarization, electric field polarization) akhoza artificially kuwononga symmetry wa zinthu pakati inversion wa CHIKWANGWANI kuwala, ndi bwino kusintha wachiwiri kuti nonlinearity ulusi kuwala. Komabe, njirayi imafuna ukadaulo wokonzekeretsa wovuta komanso wovuta, ndipo ukhoza kungokwaniritsa magawo ofananirako pamlingo wa discrete wavelengths. Mphete ya kuwala kwa fiber resonant yotengera echo wall mode imachepetsa kusangalatsa kwa ma harmonics achiwiri. Pothyola symmetry ya mawonekedwe apamwamba a fiber, ma harmonics apamwamba achiwiri mumtundu wapadera wa fiber amawonjezedwa kumlingo wina, komabe amadalira pampu ya femtosecond ndi mphamvu yapamwamba kwambiri. Choncho, kubadwa kwa zotsatira zachiwiri zosaoneka bwino muzitsulo zonse za fiber ndi kusintha kwa kusintha kwabwino, makamaka kubadwa kwa ma harmonics achiwiri mu mphamvu yochepa, kupopera kosalekeza kosalekeza, ndizovuta zomwe ziyenera kuthetsedwa. m'munda wa nonlinear CHIKWANGWANI Optics ndi zipangizo, ndi zofunika sayansi kufunika ndi lonse ntchito phindu.

Gulu lofufuza ku China lakonza dongosolo lophatikizira gallium selenide crystal phase ndi micro-nano fiber. Pogwiritsa ntchito mwayi wapamwamba wachiwiri wosasinthika komanso kuyitanitsa kwautali kwa makristasi a gallium selenide, chisangalalo chochuluka chachiwiri-harmonic ndi njira yosinthira ma frequency angapo imakwaniritsidwa, ndikupereka njira yatsopano yopititsira patsogolo njira zambiri zama parametric mu. CHIKWANGWANI ndi kukonzekera burodibandi chachiwiri harmonicmagwero a kuwala. Kusangalatsa kwamphamvu kwachiwiri kwa harmonic ndi kuchuluka kwafupipafupi mu chiwembu kumatengera zinthu zitatu zotsatirazi: mtunda wautali wolumikizana pakati pa gallium selenide ndi gallium selenide.micronano fiber, dongosolo lachiwiri lachiwiri losagwirizana ndi dongosolo lautali la gallium selenide crystal yosanjikiza, ndipo magawo ofananirako a ma frequency ofunikira komanso kuwirikiza kawiri amakhutitsidwa.

Pakuyesako, ulusi wa micro-nano wokonzedwa ndi makina owunikira moto uli ndi gawo lofananira la cone mu dongosolo la millimeter, lomwe limapereka utali wotalikirapo wotalikirapo pakuwunikira kwapampu ndi funde lachiwiri la harmonic. Polarizability yachiwiri yopanda malire ya kristalo ya gallium selenide yophatikizika imaposa 170 pm / V, yomwe ndi yapamwamba kwambiri kuposa polarizability yamkati yopanda mawonekedwe a fiber optical. Komanso, mawonekedwe aatali a gallium selenide crystal amatsimikizira kusokonezeka kwa gawo lachiwiri la ma harmonics, kupereka masewera athunthu kuti apindule ndi kutalika kwakukulu kosasunthika mu micro-nano fiber. Chofunika kwambiri, gawo lofananira pakati pa kupopera optical base mode (HE11) ndi yachiwiri ya harmonic high order mode (EH11, HE31) imazindikirika poyang'anira kukula kwa cone ndikuwongolera kufalikira kwa ma waveguide panthawi yokonzekera micro-nano fiber.

Zomwe zili pamwambazi zimayala maziko osangalatsa komanso otambalala a ma harmonics achiwiri mu micro-nano fiber. Kuyesera kukuwonetsa kuti kutulutsa kwa ma harmonics achiwiri pamlingo wa nanowatt kumatha kukwaniritsidwa pansi pa mpope wa 1550 nm picosecond pulse laser, ndipo ma harmonics achiwiri amathanso kusangalatsidwa bwino pansi pa mpope wopitilira laser wa kutalika komweko, ndipo mphamvu yapakhomo ndi monga. otsika ngati ma microwatt mazana angapo (Chithunzi 1). Kupitilira apo, kuwala kwapampu kumakulitsidwa mpaka mafunde atatu osiyanasiyana a laser yopitilira (1270/1550/1590 nm), ma harmonics atatu achiwiri (2w1, 2w2, 2w3) ndi ma siginecha atatu afupipafupi (w1+w2, w1+w3, w2+) w3) amawonedwa pamtundu uliwonse wa mafunde asanu ndi limodzi osinthika. Mwa kusintha kuwala kwa mpope ndi gwero lowala kwambiri la kuwala kotulutsa diode (SLED) ndi bandwidth ya 79.3 nm, harmonic yachiwiri yachiwiri yokhala ndi 28.3 nm imapangidwa (Chithunzi 2). Kuphatikiza apo, ngati ukadaulo woyika mpweya wamankhwala ungagwiritsidwe ntchito m'malo mwaukadaulo wosinthira wowuma mu phunziroli, ndipo magawo ochepa a makristalo a gallium selenide amatha kukulitsidwa pamwamba pa micro-nano fiber pamtunda wautali, kusinthika kwachiwiri kwa harmonic kumayembekezeredwa. kupititsidwa patsogolo.

CHITH. 1 Dongosolo lachiwiri la Harmonic Generation ndipo limabweretsa mawonekedwe amtundu wonse

Chithunzi 2 Kusanganikirana kwa mafunde ambiri ndi ma harmonics achiwiri otalikirapo pansi pa kupopera kosalekeza